The present invention relates generally to self-propelled, ground-working vehicles such as lawn mowers and, more particularly, to operator control systems for use with the same.
Various types of lawn mowers are known. For example, small, walk-behind mowers are in general use by both homeowners and professionals alike. At the other end of the spectrum are large, riding mowers adept at mowing correspondingly large and typically unobstructed areas. Between these two categories lies what is commonly referred to as xe2x80x9cmid-sizexe2x80x9d mowers.
Generally speaking, mid-size mowers are self-propelled units having a cutting width of approximately 32-60 inches. While they may be configured as either riding (including ride-on and ride-behind) or walk-behind units, walk-behind mowers potentially offer greater maneuverability. For example, walk-behind mowers are particularly efficient when mowing large lawns having numerous obstacles (e.g., trees, shrubs, flowerbeds, and the like) which necessitate intricate trimming, or when mowing lawns which may otherwise be ill-suited to high-speed riding mowers. Moreover, walk-behind mowers are often used in areas with steep slopes which may pose traction or tipping problems for riding mowers. Furthermore, mid-size, walk-behind mowers are also, in general, less expensive than riding mowers. While the present invention is directed to control systems for use with either riding or walk-behind vehicles, it will, for the sake of brevity, be described with respect to mid-size, walk-behind mowers.
One type of control system known for use with mid-size mowers uses two rearwardly extending handles each equipped with a scissors-type lever. Each lever operatively controls one of two drive wheels typically located at or near the rear corners of the cutting unit. Where the levers are configured as xe2x80x9cnormally engaged,xe2x80x9d actuating (e.g., squeezing) one of the drive levers causes disengagement and/or braking of the corresponding drive wheel, permitting the mower to turn about that wheel. Alternatively, the levers may be xe2x80x9cnormally disengagedxe2x80x9d such that actuating (e.g., squeezing) one of the drive levers causes engagement of the corresponding drive wheel.
While scissors-type lever control systems are more than adequate for their intended purpose, drawbacks remain. For instance, scissors-type levers, in general, may provide limited mechanical advantage in overcoming lever tension. Accordingly, when cutting a lawn with many trees, shrubs, or other obstacles that necessitate numerous turns, discomfort in the hands, wrists, and arms may occur. Scissors-type lever control systems may also be susceptible to variation in lever tension over the lever travel. Furthermore, depending on the position of each lever within its throw, the operator may not be able to grasp the respective lever with all fingers.
Other systems are also known. For example, U.S. Pat. No. 5,511,367 to Powers et al. and U.S. Pat. No. 5,809,755 to Velke et al. disclose control systems having a generally horizontal, transverse hand position. While addressing some of the above-identified problems, other issues with hand position and/or control actuation potentially remain.
Control systems of the present invention seek to overcome the above-identified drawbacks by providing natural hand positioning with conveniently located drive control levers. Control systems in accordance with the present invention further provide a hand position interior to the control system to reduce potential contact between the operator""s hands and external objects during operation. The drive control levers of the present invention may additionally provide substantially constant tension throughout their range of motion, resulting in drive control lever forces which are more evenly distributed throughout the operator""s hands.
In one embodiment, an operator control system for a self-propelled vehicle is provided. The operator control system includes a handle assembly including a first hand grip having a first grip axis and a second hand grip having a second grip axis. The first grip axis and the second grip axis extend upwardly and toward one another when the vehicle is in an operating configuration. A first control lever associated with the first hand grip is also included. The first control lever is pivotable about a first pivot axis, wherein the first pivot axis is substantially parallel to the first grip axis of the first hand grip. A latching device associated with the first control lever is also included and is adapted to latch the first control lever in two or more positions.
In another embodiment, an operator control system for a self-propelled vehicle is provided and includes a handle assembly including a first hand grip having a first grip axis and a second hand grip having a second grip axis. The first grip axis and the second grip axis extend upwardly, forwardly, and toward one another when the vehicle is in an operating configuration. Also provided is a first control lever associated with the first hand grip. The first control lever is pivotable about a first pivot axis, wherein the first pivot axis is substantially parallel to the first grip axis of the first hand grip. A latching device associated with the first control lever is also included. The latching device is operable to latch the first control lever in two or more positions.
In yet another embodiment, a method for controlling a self-propelled vehicle is provided. The method includes providing an operator control system including a handle assembly having a first hand grip with a first grip axis and a second hand grip with a second grip axis. The first grip axis and the second grip axis extend upwardly and toward one another when the vehicle is in an operating configuration. A first control lever associated with the first hand grip is also included. The first control lever is pivotable about a first pivot axis, wherein the first pivot axis is substantially parallel to the first grip axis of the first hand grip. The handle assembly also includes a first latching device associated with the first control lever, where the first latching device is operable to latch the first control lever in at least a first position and a second position. The method also includes: grasping the first control lever with an operator""s first hand; manipulating the first control lever to the first position with the operator""s first hand; and manipulating the first latching device to latch the first control lever in the first position.
In still yet another embodiment, an operator control system for a self-propelled power mower is provided. In this embodiment, the control system may include a handle assembly including a first hand grip having a first grip axis and a second hand grip having a second grip axis. The first grip axis and the second grip axis are substantially coplanar and extend upwardly, forwardly, and toward one another when the mower is in an operating configuration. The control system may also include a first control lever associated with the first hand grip, where the first control lever is pivotable about a first pivot axis, the first pivot axis being substantially parallel to the first grip axis of the first hand grip. A first latching device including a generally hook-shaped member pivotally coupled to the first hand grip is also included. The first latching device is operable to pivot about an axis generally coaxial with the first grip axis. The first latching device is adapted to latch the first control lever in at least a first position and a second position.